Destination designator system for material handling apparatus



c. E. KONRAD 1970 DESTINATION DESIGNATOR SYSTEM FOR 3525867 MATERIAL HANDLING APPARATUS Filed July 16, 1968 3 Sheets-Sheet 1 Ii llllllllllllllllllllllllllllll ii IIIIIH 5/ 1 F llllllllllllllllllllllll *UIIRWFITIHIHIIIIIIIIIIH "Ill W WW Q P m WIIIIIIWUIMMI 82 83 84 5 v s 9 s s 2' s s 5 V 510, C: 51 CD INVENTOR.

' CHARLES E. KONRAD F' G. 2 BY v Aug. 25, 1970 c. E. KONRAD DESTINATION DESIGNATOR SYSTEM FOR MATERIAL HANDLING APPARATUS 5 Sheets-Sheet 2 Filed July 16, 1968 FIG.5

INVENTOR. CHARLES E KONRAD Aug. 25, 1970 c. E. KONRAD 3,525,867

DESTINATION DESIGNATOR SYSTEM FOR 7 MATERIAL HANDLING APPARATUS 3 Sheets-Sheet 3 Filed July 16, 1968 D Rm 0N 40 958 mm ozmhzwu E :1 a We 1 S L 2 mo mo m R A H c m: I mwmw m zut3w $25551 J zorfimma A m: I v M a. a. 3 m. .2. 28 A m n: 40x58 woke: Qz 553E 183528 I: w w \J m2 2. mm 1 mm. w E QM?) 6528 mEbE 1 biz. 0596 556mm Kim v r E 29203 2 j United States Patent US. Cl. 250-209 Claims ABSTRACT OF THE DISCLOSURE Apparatus for preselecting or identifying a storage location among a plurality of linearly accessible storage positions in a storage complex for the purpose of loading or unloading materials from storage including at each location an open channel member capable of being encoded via pre-cut projections or tabs defining the sides of the channel when coded, the uncoded tabs being retained in the plane of the channel base, or severed therefrom, and the tabs forming one side of the channel providing a timing means for a scanning transducer receiving its data from the coded tabs forming the other side of the channel, the transducer being a composite structure straddling both sides of the channel and having a photocell on the outside of each side of the channel and a common light source inside the channel scanning the aforesaid coded tabs of each side thereby interrupting the light source, and the transducer being carried by a vehicle transporting storage material.

BACKGROUND OF THE INVENTION In stacker crane installations where a crane or loading equipment is guided to storage bins or storage locations, positioned on either side of the aisle through which the crane moves, it has become increasingly more necessary to automate the control of the destination addressing selection of the cane. To accomplish this the storage compartments or storage bins are provided with some form of coded numbers recognizable by the crane control which is provided with means for reading this coded number and comparing it with the stored coded number representing the destination address to which the crane must travel for retrieval or delivery of a load. So long as the codes read do not match the stored destination addressing code the crane continues its travel, however, when the matching code has been found and read the motion of the crane is halted.

Many diiterent types of coding means have in the past been used, for example, mechanical type of bin identification, wherein a wheel is guided along a track having various combinations of notches therein, located in proximity to the storage compartments, whereby a code representing the address of storage compartmetns is provided. Similarly a series of switches which are actuated by the passage of the crane wherein the various storage locations are represented by a predetermined combination of switch closures and the crane is halted when the correct combination of switch closures has been found. The mechanical type of bin identification is subject to wear, high initial installation costs, and is not readily changed when once installed.

Another type of address control uses reflected light applied to a series of short lengths of tape which are attached adjacent to each other to the storage location. The tapes are black and white and are so arranged to form a code by combining the black and white tapes in a predetermined configuration. A light source illuminating the tapes and a light sensor adapted to detecting the difference of light absorption of the black and white tapes produces a signal sequence which corresponds to a code presented ice by combination of the tapes. With time, however, dirt accumulates on the tapes and difference of absorption diminishes, resulting in false readings by the light sensor. Increasing the sensitivity of the light sensors in this case may also produce false readings since it may produce signals which are due to light absorption and reflection characteristics of elements not related to the coding tape.

Magnetic coding is yet another method of producing a destination address. In this the code is applied to a magnetic tape or card attached to the storage bin location and read by a magnetic sensor as the crane passes the various storage bin locations. The most serious disadvantage of this method is the close tolerance required between the magnetic and the coded card. Access of the magnetic sensor to the magnetically coded card or tape must be held within an inch.

SUMMARY OF THE INVENTION To overcome these difiiculties the present invention provides a coding system which utilizes incident light, wherein a traveling light source, produces a light beam which is interrupted by a series of opaque tabs positioned at the storage locations. A light sensor, adapted to receive the light beam and producing electrical signals in response to interruption thereof, has an electrical circuit which is actuated each time the light beam is in opposition to one of the tabs or tab locations.

In operation some of the tabs are removed from their location so that in that position the light beam will not be interrupted, and the signal thus produced dilfers from that which is produced when the light beam is interrupted.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view of light sources and light sensors passing through a coded tab channel.

FIG. 2 is the tab channel shown in the flat form, from which it is constructed.

FIG. 3 is a pictorial view of the tab channel modified with centering means.

FIG. 4 is a block diagram showing a control circuit adapted to utilize signals produced as a result of light beam interruption by the tabs of the coded tab channel.

FIG. 5 shows an alternate method of constructing a coded tab channel.

DESCRIPTION FIG. 1 shows a first light source 11 having a set of lenses 21 provided in each of its sides 19 and 20 for the projection of light beams to a first and second light sensor 13 and 15 located at either side of light source 11. Each of the light sensors 13 and 15 has a lens system such as indicated by numeral 23 shown on unit 15, which is aligned with the lenses 21 of light source 11. Both light sensors 13 and 15 and light source 11 are attached to a common support 17 which in turn is attached to a sup port 22 (shown dashed) movable with the apparatus (not shown) to which it is assembled.

A second light source 31 having a set of lenses 32 provided in both of its sides 34 and 36 projects a light beam to a third and fourth light sensor 33 and 35 located at either side thereof. Each of the light sensors 33 and 35 having a lens system such as indicated by numeral 38 shown on unit 35 for receiving the light rays, which is aligned with the lenses on light source 31. Light source 31 and light sensors 33 and 35 are attached to a common support 37 which in turn is attached to the same support 22 (shown in dashed lines) to which the common support 17 is attached.

A channel 51 having its sides notched in a predetermined configuration as shown in FIGS. 1 and 2 is placed so that movement of the light sources 11 and 31 is along its axes in the space between the notched sides. The light sensors 13, 15 and 33, 35 are so positioned with respect to the light sources 11 and 31, respectively, that the notched sides of the channel 51 are interposed between the light sources and their respective light sensors, and the light beams emanating from the light sources are interrupted by the tabs formed on the notched sides of channel 51 as light sources 11 and 31 move through the channel. The channel 51 originates in the flat form as shown in FIG. 2. It has ten notches 53-62 along one side of center rib 51a, thereby forming eleven tabs 63-72. The other side of the channel has ten notches 75-84 along the center rib 51a forming nine tabs 85-93. The center lines of the tabs 64-72 are aligned with the center lines of tabs 85-93 leaving tabs 63 and 73 without equivalent tabs in opposition.

After forming the channel by bending the tabs on either side of the center rib 51a at a 90 angle thereto, three functions are provided: (1) A clock pulse or sequence pulse is provided by tabs 85-93 each time the light beam from light source 11 to light sensor 15 is interrupted by one of these tabs. (2) A code is provided serially by tabs 64-72 each time the light beam from light source 11 to light sensor 13 is interrupted by one of these tabs. (3) Centering information, hence information which indicates where the movable apparatus (not shown) to which the light sources and their respective light sensors are attached must be stopped, is provided by tabs 63 and 73.

Referring now to'FIG. 1, support 17 and 37 move with an apparatus, such as the stacker crane or a conveyor (not shown) to which they are attached. Channel 51 and others like it are fastened into position at each of the loading stations which are served by, for example, the stacker crane (not shown). In use some of the tabs of the channel 51 are bent away from the 90 position or may be removed completely, leaving an opening or tab space. Each loading station has its own combination or code which depends on the order in which the tab and tab spaces are ararnged on the coding side of the channel. For example, in FIG. 1 tabs 66, 68, 69, and 72 have been bent away from the 90 angle whereby tab spaces are formed in the places thereof. The light beam from light source 11 to light sensor 13 is not interrupted in these spaces thus as the light source 11 travels down the center of the channel in the direction indicated by arrow 50, the light beam emanating from light source 11 through lens 21 to light sensor 13 is broken by the tabs 73, 71, 70,'67, 65, 64 and 63; but is maintained when it passes tab spaces 72, 69, 68 and 66. The light beam applied to light sensor 15 is broken by every one of the tabs 85-93 as they interpose between the light source 11 and light sensor 15 thereby producing a signal which the circuitry (described later) is arranged to utilize for forming clock pulses which cause the circuitry to read the condition of light sensor 13, thereby establishing information equivalent to the code set in the channel by the combination of tabs and tab spaces 64-72. For the purpose of this example, let the signal derived from the light sensor when the light is applied thereto be a positive voltage and the signal which is derived from the light sensor when the light is interrupted be a zero voltage signal. Then if the positive signal is considered to be a binary one signal and the zero voltage signal is considered to be a binary zero signal, a binary number is developed as the light source passes through the channel. In the example, then, where the code tabs 66, 68, 69 and 72 are bent flat, a code is developed as the light source travels past tabs 64-72 each time a light beam from light source 11 to light sensor 15 is interrupted by one of the clock tabs 58-93. Thus, in the case of tab space 72, the light beam is applied to the light sensor since tab 72 is not there to obstruct the passage of the light to a light sensor 13 which therefore results in a positive voltage signal, hence a binary one signal.

Continued movement of the light source 13 will cause the light sensor to produce a binary zero as tab 72 interrupts the light beam, a binary zero for tab 70, a binary one signal for tab spaces 69 and 68 and a binary zero signal for tab 67, a binary one for tab space 66 and binary zero signals for tabs 65 and 64. The final code read by the light sensor 13 during a travel through the entire channel reading all the tabs and tab spaces produce a binary number 100110100. The clock pulse tabs -93 are made narrower than the code tabs 64-72 to provide assurance that the signal produced by light sensor 13 as it reads the code is accepted only after the light sensor 1s aligned with the center of the code tab position.

Qentering tabs 63 and 73 perform the function of designating the moment when brakes to the crane should be applied, so that motion of the crane is halted at the right position thereof. The center line distance between these tabs is such that the light beams from both lights 11 and 31 through light sensors 13 and 33, respectively, are simultaneously interrupted. The distance between the llght sources is adjustable to perform this function. Therefore, as the light source 11 continues to travel down the channel 51 in the direction indicated by arrow 50, its light beam applied to light sensor 13 is interrupted simultaneously to the interruption of light beam from light source 31 to light sensor 33. When both light sensors 13 and 33 fail to produce a binary one signal simultaneously which is caused by the interruption of centering tabs 63 and 73, circuitry provided to accept these signals (described later) will cause the crane to halt its motion. Accuracy of stopping location may be increased by adustmg the center line distance of light sources 11 and 31 to a slightly larger dimension than that of the center l1ne distance between centering tabs 63 and 73, so that thedistance traveled by the light source in the period during which the light beams from both light sources 11 and 31 are interrupted is shorter.

In stacker crane arrangements, one crane is usually used for the loading and unloading of material in and out of storage compartments which are located on either slde of the aisle through which the stacker crane moves. In this type of arrangement only one coding system havmg lights and sensors as described above is used for positionlng the crane at the proper location with respect to one side or the other side of the aisle. It follows then that during the installation of such stacker crane storage compartment the alignment of storage compartments in corresponding locations on either side of the aisles must be accurately maintained, so that the crane may be stopped to load and unload in only one position regardless of the selection of the side of the aisle in which the storage compartment is located. The present invention will allow greater tolerance of the alignment of corresponding storage compartments at either side of the aisle. FIG. 3 shows a centering tab assembly for attachment to channel 51 which will provide independent centering for bothsides of the aisle. The assembly 95 has provided therein a pair of mounting holes 97 and 99 which coinclde With the mounting slots 101 and 103, respectively, in the centering rib 51a of channel 51. The slots thereby provlde a sliding adjustment for centering assembly 95 along the axis of channel 51. Tabs 105 and 107 which are an integral part of centering assembly 95 provide the dentical function for the left side of the aisle as centermg tabs 63 and 73 provide for the right hand side of the aisle (FIG. 1) when the centering assembly is mounted on to channel 51 as shown in FIG. 3. If alignment of the storage compartments (not shown) is inaccurate, Wlthlll limits, the adjustment of centering assembly 95 with respect to the centering tabs 63 and 73 will allow compensation for this inaccuracy by providing the independent centering of the crane for either side of the aisle. Circuitry, described later, through the use of coding provides direction to the loading mechanism of the crane so that material will automatically be stored on either the left or the right hand side of the aisle. For example, the least significant bit in the location number can be made a binary one for storage in compartments on the right hand side of the aisle so that a binary zero then will be assigned to storage in the left hand side of the aisle. In the example where the code number was presented as 100110100, the storage compartment will have to be on the left hand side of the aisle, since the least significant bit of that binary number is a zero. The centering function for this location is then automatically transferred to light sensors and 35 which when simultaneously producing binary zero signals through the interruption of centering tabs 105 and 107 will cause the motion of the crane to be halted.

Provision is made for reading the code when approached from either end of channel 51. For example, let the direction indicated by arrow 50 in FIG. 1 be the forward direction; then the direction opposite thereto will be the reverse direction. When the crane with the light sources 11 and 31 and respective light sensors attached thereto moves in the forward direction, the light beam from light source 11 to light sensor 13 is the first to be interrupted by centering tab 73. Referring now to FIGS. 1 and 4 where in this situation a zero signal produced by light sensor 13 is applied to direction switch 111 which operates to load the reversing shift register 113 in the forward direction by applying the signal derived from light sensor 13 to the terminal 115. When the crane moves in the reverse direction as indicated by arrow 117, light sensor 13 is the first to produce a zero signal when light beam from light source 31 is first interrupted by centering tab 63, which causes direction switch 111 to switch its output to terminal 119 on the reversing shift register 113 thereby causing this reversing shift register to accumulate the code information in the reverse direction. As light sources move through the coded channel 51 and the code thereby presented is accumulated serially by the reversing shift register 113 each time clock pulses produced by one of the light sensors 15 or 35, depending on the direction of motion, is applied to terminal 121. Continued travel of the light sources 11 and 31 and their respective light sensors will eventually cause the light beams from both light sources 11 and 31 to light sensors 13 and 33 to be interrupted. When the interruption of both light beams occur simultaneously, zero signals from the light sensors involved are then applied to an OR circuit 123 which in turn will cause a zero signal to be applied to centering control circuit 125 which converts this zero signal to a one signal and applies this to AND circuit 127. Similarly, when the opposite side of the aisle is selected for storage the light beams from light sources 11 and 31 to light sensors 15 and 35, respectively, will simultaneously be interrupted by tabs 105 and 107 of centering assembly 95 thereby causing these light sensors to apply zero signals to OR circuit 141 which in turn applies a zero signal to centering control 125. The input shift register 131 having the location selection coded therein will apply a zero signal to centering control 125. With two zero signals applied thereto, centering control 125 will produce a one signal and apply this to AND circuit 127.

The location input signal 129 containing the storage location involved is applied to input shift register 131 and the contents thereof is compared with the contents of the reversing shift register 113 in comparator 133 each time a clock pulse occurs. The resulting output from the comparator is then applied to AND circuit 127. If the contents of both shift registers 113 and 131 is the same, the cornparator 133 will produce a one signal. With two binary one signals applied to its input terminal, AND circuit 127 produces a one circuit which is applied to the traverse motor control 137 causing motion of the crane (not shown) to halt. If the contents of shift register 113 and 131 is not the same, the zero signal output from the comparator will result in a zero signal output from AND circuit 127 causing the continued motion of the crane (not shown).

The loading motor is provided for placing and retrieving a load from the actual storage compartment and must therefore be directed to the side of the aisle wherein the storage compartment is locatedjThe contents of the location shift register 131 therefore applies the appropriate signal to the loading motor control 137 thereby indicating the direction in which the loading motor (not shown) must be directed to place or retrieve the object to be loaded. When the traverse motor has halted the motion of the crane, a signal 136 from the traverse motor control is applied to the loading motor control 137 thereby causing the motor (not shown) to perform its functions.

The form of control described heretofore is merely an example of one method of the use of coded tab channel 51. It is, of course, also possible to utilize this type of coding method in a parallel reading equivalent of the described method by halting the motion of the crane when both light beams from light sources 11 and 31 to light sensors 13 and 33, respectively, are simultaneously interrupted by the centering tabs and then applying a reading signal to take a reading of all of the coded tabs provided in the channel simultaneously and utilizing the thus provided signals in appropriate circuitry to cause appropriate action to be taken. Utilizing the parallel method of reading the code would eliminate the clock pulse tabs from the channel since this merely creates pulses for serially reading of the code and storing this in the reversing shift register 113.

Referring now to FIG. 5 wherein the coded tabbed channel is shown as an alternate method of producing a binary number representing storage locations. Only the coding side of the channel is shown having two identical halves A and B of center rib 201. Sides A and B are coded inversely identical, that is, that passage of the light and their respective light sensors will read the code in the same order regardless of the direction of travel; i.e., when light sources and light sensors enter in the direction indicated by arrow 203, the tab 205 is first to interrupt the light beam between the light source and their respective light sensor. Tab 206 is bent away from the angle forming the channel and therefore provides a tab space or a binary one signal. Tab 207 interrupts the light beam as well as tab 208 thereby causing the light sensor to produce two binary zero signals. Tab 209 has been removed from the channel therefore providing a binary one signal since the light beam is not interrupted thereby. Tab 210 and 211 both interrupt light beams whereby a binary zero signal is produced through each of them. The number therefore accumulated by the passage of the light source and the respective light sensor will be 0100100 when the light source and the light sensor travel in the direction of the arrow as indicated by arrow 203. If the light sensor and light source enter the channel from the direction indicated by arrow 221, tab 223 is first to interrupt the light beam. Tab 224 is bent away from the 90 angle whereby a tab space is provided, thus producing a one signal. Tabs 225 and 226 cause the light sensor to produce two binary zero signals. Tab 227 has been removed from the channel whereby a tab space is formed which causes the light sensor to produce a binary one signal. Tabs 229 and 230 each produce binary zero signals since they interrupt the light beam from the light source to the light sensor. The code thus accumulated is 0100100 which is identical to the one produced when the light sources and light sensors moved in the direction indicated by arrow 203. The reversing counter and direction switch used by the first method is therefore unnecessary since the code is accumulated in the same order regardless of the direction in which the light sensors and light sources travel. Centering is performed by a slidably, adjustable tab 235 which interrupts a pair of light beams simultaneously.

The use of light sources and light sensors is only one of several methods which may be used in accumulating the coded number indicating the storage location. Other methods such as acoustical or magnetic sensing may be performed in a similar manner as described above with light sources and light sensors. In the case of the magnetic method of accumulating the coded number, the channel would have to be manufactured from a magnetic type material such as steel. The inductive reactance of a coil would be effected by the proximity of a tab as the coil passed through the channel in the same manner as light sources do in the method described above.

While the invention has been explained and described with the aid of particular embodiments thereof, it will be understood that the invention is not limited thereby and that mnay modifications retaining and utilizing the spirit thereof without departing essentially therefrom will occur to those skilled in the art in applying the invention to specific operating environments and conditions. It is therefore contemplated by the appended claims to cover all such modifications as fall within the scope and spirit of the invention.

What is claimed is:

1. In a storage complex having a series of separated storage locations a first member at each destination comprising a plurality of preformed, spaced tabs projecting therefrom, said tabs capable of being bent selectively at their junctures with said first member to provide an identifying coding representative of said storage location; a second member at each destination comprising a plurality of preformed, spaced tabs projecting therefrom, said tabs bent at their juncture with said second member; a first transducer responsive to the presence of said tabs of said first member for identifying said location; a second transducer responsive to the presence of said tabs of said second member for providing a timing sequence for initiating said first transducing and identifying the coding; and a vehicle for translating said first and second transducers over all of said storage locations.

2. The apparatus as claimed in claim 1 modified to provide the said first member at each destination with a first and last preformed, spaced tab projection; a third transducer spaced away from said first transducer at. a distance equal to the distance between that first and last spaced tab; said third transducer being responsive to the presence of said last tab of said first member and cooperating with said first transducer for providing an electrical signal to stop said vehicle when the presence of said first tab is detected by said first transducer and the presence of said last tab is detected simultaneously by said third transducer.

3. The invention claimed in claim 1 wherein said first and second members are combined to form a flat, elongate member having a plurality of preformed, spaced tabs projecting from each side of said member; said tabs of both sides capable of being bent at their juncture with said member to form therewith a channel structure; the tabs on one side being bent selectively to provide a coding representative of said storage location and the tabs on the other side being bent to provide a timing sequence for identifying the coding.

4. The apparatus as claimed in claim 3 wherein the first and second transducers have a pair of photocells, one for each side of said channel, and a common light source therebetween arranged to be interrupted by the tabs of both sides of said channel coacting with their respective photocells for identifying said location.

5. In a storage complex having a series of separated storage locations an identifying member at each destination comprising a flat, elongated member having a plurality of preformed, spaced tabs projecting from each side of said member, said tabs of both sides capable of being bent attheir junctures with said member to form therewith a channel structure, the tabs on one side being bent selectively to provide a coding representative of the said storage location and the tabs of the other side being but to provide a timing sequence for identifying the coding, a transducer for scanning said channel structure having a pair of photocells, one for each side of said channel, and having a common light source therebetween arranged to be interrupted by the tabs of both sides of said channel coacting with their respective photocells for identifying said location, and a vehicle for translating said transducer over all said storage locations.

References Cited UNITED STATES PATENTS 3,086,121 4/1963 Cockrell 250-209 X 3,324,301 6/ 1967 Goldberg 250223 3,394,262 7/1968 Kintigh 250219 3,405,818 10/1968 Humenuk 214l6.4

ROBERT SEGAL, Primary Examiner E. R. LA ROCHE, Assistant Examiner US. Cl. X.R. 

